Groups > comp.lang.python > #71924

Re: hashing strings to integers (was: hashing strings to integers for sqlite3 keys)

Path	csiph.com!usenet.pasdenom.info!aioe.org!news.stack.nl!newsfeed.xs4all.nl!newsfeed4a.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path	<rosuav@gmail.com>
X-Original-To	python-list@python.org
Delivered-To	python-list@mail.python.org
X-Spam-Status	OK 0.000
X-Spam-Evidence	'H': 1.00; 'S': 0.00; 'that?': 0.05; 'explicit': 0.07; 'string': 0.09; 'arrays': 0.09; 'subject:keys': 0.09; 'cc:addr:python-list': 0.11; 'python': 0.11; '23,': 0.16; 'adam': 0.16; 'dict': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'hashes': 0.16; 'lookups': 0.16; 'simplicity.': 0.16; 'subject: \n ': 0.16; 'subject:sqlite3': 0.16; 'wrote:': 0.18; 'bit': 0.19; 'bonus': 0.22; 'cc:addr:python.org': 0.22; 'byte': 0.24; 'integer': 0.24; 'cc:2**0': 0.24; "i've": 0.25; 'header:In-Reply-To:1': 0.27; 'involving': 0.30; 'message- id:@mail.gmail.com': 0.30; 'equality': 0.31; 'fri,': 0.33; 'guess': 0.33; 'subject: (': 0.35; 'received:google.com': 0.35; 'pm,': 0.38; 'though,': 0.39; 'to:none': 0.92
DKIM-Signature	v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:cc :content-type; bh=MlHFEOXIJuH8zUlL1vBF3ilrCIfVvmXRIyi5dA7vV/Q=; b=cuWc50tO5xYbvEwD7wNGPAxEmL7mUeyx5pZHxKUFKAXQiBjAX1DNcIDp6B3o5LU73R 5ePwv3TFAMg49yNK79rsbYSHoTtvSoxbwcZ5z2ugPAq1HFu/B6ssMKQVWvt7jw/QLF2/ NWlhaCGvrr2xqZ2tOu1rsa7F2Z7iZYgXuG2MG8ngZIFfijUp1BzOU5Q4x6rGZCU4SDdW bwReKrBWwBsMG+soDGPa6phLWzedTzIn9meWBVeqKZhKmFK9u8Do0Zr9323rkPCONPPE ik6gU4pYAaFjd3zTVdlp+bBc3DwWATop5AZ4wL7VDk1x8anmsDbDd8X7u0gi6snJlrFi uKxA==
MIME-Version	1.0
X-Received	by 10.52.104.7 with SMTP id ga7mr2928501vdb.29.1400842770202; Fri, 23 May 2014 03:59:30 -0700 (PDT)
In-Reply-To	<sck35bxdc5.ln2@news.ducksburg.com>
References	<jn415bx6uf.ln2@news.ducksburg.com> <mailman.10220.1400764235.18130.python-list@python.org> <05c15bxrpj.ln2@news.ducksburg.com> <mailman.10223.1400768058.18130.python-list@python.org> <k9f15bxoql.ln2@news.ducksburg.com> <mailman.10225.1400772863.18130.python-list@python.org> <sck35bxdc5.ln2@news.ducksburg.com>
Date	Fri, 23 May 2014 20:59:30 +1000
Subject	Re: hashing strings to integers (was: hashing strings to integers for sqlite3 keys)
From	Chris Angelico <rosuav@gmail.com>
Cc	"python-list@python.org" <python-list@python.org>
Content-Type	text/plain; charset=UTF-8
X-BeenThere	python-list@python.org
X-Mailman-Version	2.1.15
Precedence	list
List-Id	General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe	<https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive	<http://mail.python.org/pipermail/python-list/>
List-Post	<mailto:python-list@python.org>
List-Help	<mailto:python-list-request@python.org?subject=help>
List-Subscribe	<https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups	comp.lang.python
Message-ID	<mailman.10239.1400842778.18130.python-list@python.org> (permalink)
Lines	11
NNTP-Posting-Host	2001:888:2000:d::a6
X-Trace	1400842778 news.xs4all.nl 2846 [2001:888:2000:d::a6]:41294
X-Complaints-To	abuse@xs4all.nl
Xref	csiph.com comp.lang.python:71924

Show key headers only | View raw

On Fri, May 23, 2014 at 8:27 PM, Adam Funk <a24061@ducksburg.com> wrote:
> I've also used hashes of strings for other things involving
> deduplication or fast lookups (because integer equality is faster than
> string equality).  I guess if it's just for deduplication, though, a
> set of byte arrays is as good as a set of int?

Want a better way to do that? Use a set or dict and let Python do the
hashing. It'll be every bit as fast as explicit hashing, plus you get
the bonus of simplicity.

ChrisA

Thread

hashing strings to integers for sqlite3 keys Adam Funk <a24061@ducksburg.com> - 2014-05-22 12:47 +0100
  Re: hashing strings to integers for sqlite3 keys Peter Otten <__peter__@web.de> - 2014-05-22 14:58 +0200
    Re: hashing strings to integers for sqlite3 keys Adam Funk <a24061@ducksburg.com> - 2014-05-22 14:41 +0100
      Re: hashing strings to integers for sqlite3 keys Chris Angelico <rosuav@gmail.com> - 2014-05-23 00:08 +1000
        Re: hashing strings to integers for sqlite3 keys Adam Funk <a24061@ducksburg.com> - 2014-05-22 15:40 +0100
  Re: hashing strings to integers for sqlite3 keys Chris Angelico <rosuav@gmail.com> - 2014-05-22 23:03 +1000
    Re: hashing strings to integers for sqlite3 keys Adam Funk <a24061@ducksburg.com> - 2014-05-22 14:47 +0100
  Re: hashing strings to integers for sqlite3 keys Tim Chase <python.list@tim.thechases.com> - 2014-05-22 08:09 -0500
    Re: hashing strings to integers for sqlite3 keys Adam Funk <a24061@ducksburg.com> - 2014-05-22 14:54 +0100
      Re: hashing strings to integers for sqlite3 keys Chris Angelico <rosuav@gmail.com> - 2014-05-23 00:14 +1000
        Re: hashing strings to integers for sqlite3 keys Adam Funk <a24061@ducksburg.com> - 2014-05-22 15:47 +0100
          Re: hashing strings to integers for sqlite3 keys Chris Angelico <rosuav@gmail.com> - 2014-05-23 01:09 +1000
          Re: hashing strings to integers for sqlite3 keys Peter Otten <__peter__@web.de> - 2014-05-22 17:34 +0200
            hashing strings to integers (was: hashing strings to integers for sqlite3 keys) Adam Funk <a24061@ducksburg.com> - 2014-05-23 11:27 +0100
              Re: hashing strings to integers Adam Funk <a24061@ducksburg.com> - 2014-05-23 11:36 +0100
                Re: hashing strings to integers Chris Angelico <rosuav@gmail.com> - 2014-05-23 21:01 +1000
              Re: hashing strings to integers (was: hashing strings to integers for sqlite3 keys) Chris Angelico <rosuav@gmail.com> - 2014-05-23 20:59 +1000
                Re: hashing strings to integers Adam Funk <a24061@ducksburg.com> - 2014-05-27 16:13 +0100
                Re: hashing strings to integers Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-27 17:02 +0000
                Re: hashing strings to integers Chris Angelico <rosuav@gmail.com> - 2014-05-28 05:16 +1000
                Re: hashing strings to integers Dan Sommers <dan@tombstonezero.net> - 2014-05-28 01:55 +0000
                Re: hashing strings to integers Adam Funk <a24061@ducksburg.com> - 2014-06-03 11:29 +0100
                Re: hashing strings to integers Adam Funk <a24061@ducksburg.com> - 2014-06-03 11:32 +0100
              Re: hashing strings to integers Terry Reedy <tjreedy@udel.edu> - 2014-05-23 15:10 -0400
                Re: hashing strings to integers Adam Funk <a24061@ducksburg.com> - 2014-05-27 16:20 +0100
  Re: hashing strings to integers for sqlite3 keys alister <alister.nospam.ware@ntlworld.com> - 2014-05-22 14:48 +0000

csiph-web